feat(cpp): resolve inheritance-lattice member lookup

gitnexus/bench/scope-capture/baselines.json

@@ -18,11 +18,11 @@
     "_rebaselined": "#1919 open-language coverage: new lang-resolution fixtures + intended capture additions (F5/F9 c-cpp, F26/F28/F29 dart, F47/F48/F49/F51/F52 kotlin, F75/F79 swift). Fingerprint-only drift; scaling_ratio ~1.0 (linear, no perf regression)."
   },
   "cpp": {
-    "fingerprint": "fd3d3768cdebbb4767d7cf18b8d2df19d61de969c816d7f4d6b599f947811356",
+    "fingerprint": "f56625342f73e182170e2c964d538e316c079fa6e9466a7f076bff2ebcf8aac4",
     "scaling_budget": 1.5,
     "_added": "#1956: cpp added to the scope-capture bench (was UNBENCHED). Heritage-bearing scale source (: public Base, public Mixin) drives emitCppInheritanceCaptures at scale. Adding it exposed + fixed a pre-existing O(n^2) findNodeAtRange root-walk in cpp/captures.ts (~12 sites, threaded c.node, byte-identical over 263 cpp-* fixtures); scaling 2.30 -> 1.12.",
     "_rebaselined": "#1919 open-language coverage: new lang-resolution fixtures + intended capture additions (F5/F9 c-cpp, F26/F28/F29 dart, F47/F48/F49/F51/F52 kotlin, F75/F79 swift). Fingerprint-only drift; scaling_ratio ~1.0 (linear, no perf regression).",
-    "_note": "#1975: + cpp-out-of-line-class fixture, fixture_count 263->265. #1990: + cpp-adl-ns-plus-hidden-friend-same-name fixture (ADL hidden-friend + namespace-callable merge parity test). Pure fixture-corpus drift — no scope-extractor change; existing fixtures' captures byte-identical. fixture_count 265->267. #1995: + cpp-union-nested-tail-collision and cpp-anon-ns-tail-collision fixtures — pure fixture-corpus drift; fixture_count 270->272, fingerprint 538e8be->d63ded6. #1993: + cpp-cross-namespace-same-tail fixture — pure fixture-corpus drift; fixture_count 272->273, fingerprint d63ded6->6d6207ae."
+    "_note": "#1975: + cpp-out-of-line-class fixture, fixture_count 263->265. #1990: + cpp-adl-ns-plus-hidden-friend-same-name fixture (ADL hidden-friend + namespace-callable merge parity test). Pure fixture-corpus drift — no scope-extractor change; existing fixtures' captures byte-identical. fixture_count 265->267. #1995: + cpp-union-nested-tail-collision and cpp-anon-ns-tail-collision fixtures — pure fixture-corpus drift; fixture_count 270->272, fingerprint 538e8be->d63ded6. #1993: + cpp-cross-namespace-same-tail fixture — pure fixture-corpus drift; fixture_count 272->273, fingerprint d63ded6->6d6207ae. #2077 review follow-up: cpp-member-lattice adds cross-file, qualified-base, nested-template, inherited-using, this-receiver, and non-virtual-override regressions; fixture_count 274->275. Capture scaling remains linear (1.134 < 1.5)."
   },
   "csharp": {
     "_rebaselined": "#1956 synth-widening: + csharp-qualified-base fixture; the synth now walks record_declaration + struct_declaration base_lists and handles alias_qualified_name (matching the #1940 legacy leg), so record/struct heritage now emits. csharp-record-base gains a record inherits capture. (record->record SAME-namespace EXTENDS is a separate registry resolution gap, tracked as follow-up.) Linear (~1.00). (Earlier #1956: heritage-bearing scale source.) | #942: scope-resolution-only cleanup reworded fixture comments; capture byte-positions shift, capture LOGIC unchanged. | #1924 F16: record primary-constructor base bindings now exclude constructor arguments; capture fingerprint changes, scaling remains linear. | #2036 review follow-up: csharp-record-base now exercises primary-constructor base dispatch end to end; +2 capture groups, scaling remains linear.",

gitnexus/src/core/ingestion/languages/cpp/capture-side-channel.ts

@@ -42,6 +42,11 @@ import {
   applyCppTwoPhaseSideChannel,
   type CppTwoPhaseSideChannel,
 } from './two-phase-lookup.js';
+import {
+  applyCppMemberLookupSideChannel,
+  collectCppMemberLookupSideChannel,
+  type CppMemberLookupSideChannel,
+} from './member-lookup.js';
 
 /**
  * Plain JSON-serializable composite of every C++ capture-time side-channel
@@ -62,6 +67,7 @@ export interface CppCaptureSideChannel {
   readonly inlineNamespaceRanges: readonly string[];
   readonly fileLocal: CppFileLocalSideChannel;
   readonly twoPhase: CppTwoPhaseSideChannel;
+  readonly memberLookup: CppMemberLookupSideChannel;
 }
 
 /**
@@ -74,6 +80,7 @@ export function collectCppCaptureSideChannel(filePath: string): CppCaptureSideCh
   const inlineNamespaceRanges = collectCppInlineNamespaceSideChannel(filePath);
   const fileLocal = collectCppFileLocalSideChannel(filePath);
   const twoPhase = collectCppTwoPhaseSideChannel(filePath);
+  const memberLookup = collectCppMemberLookupSideChannel(filePath);
 
   const isEmpty =
     adl.argInfoBySite.length === 0 &&
@@ -82,10 +89,12 @@ export function collectCppCaptureSideChannel(filePath: string): CppCaptureSideCh
     fileLocal.fileLocalNames.length === 0 &&
     fileLocal.anonymousNamespaceRanges.length === 0 &&
     twoPhase.dependentBases.length === 0 &&
-    twoPhase.dependentPackBaseClasses.length === 0;
+    twoPhase.dependentPackBaseClasses.length === 0 &&
+    memberLookup.baseEdges.length === 0 &&
+    memberLookup.memberUsings.length === 0;
   if (isEmpty) return undefined;
 
-  return { kind: 'cpp', adl, inlineNamespaceRanges, fileLocal, twoPhase };
+  return { kind: 'cpp', adl, inlineNamespaceRanges, fileLocal, twoPhase, memberLookup };
 }
 
 /**
@@ -108,4 +117,7 @@ export function applyCppCaptureSideChannel(parsed: ParsedFile): void {
   }
   if (data.fileLocal !== undefined) applyCppFileLocalSideChannel(parsed.filePath, data.fileLocal);
   if (data.twoPhase !== undefined) applyCppTwoPhaseSideChannel(parsed.filePath, data.twoPhase);
+  if (data.memberLookup !== undefined) {
+    applyCppMemberLookupSideChannel(parsed.filePath, data.memberLookup);
+  }
 }

gitnexus/src/core/ingestion/languages/cpp/captures.ts

@@ -20,6 +20,7 @@ import { markCppDependentBase, markCppDependentPackBase } from './two-phase-look
 import { markCppAdlSiteArgs, markCppAdlSiteNoAdl, type CppAdlArgInfo } from './adl.js';
 import { markCppInlineNamespaceRange } from './inline-namespaces.js';
 import { extractCppTemplateConstraints } from './constraint-extractor.js';
+import { captureCppMemberLookupFacts } from './member-lookup.js';
 
 export function emitCppScopeCaptures(
   sourceText: string,
@@ -464,6 +465,7 @@ export function emitCppScopeCaptures(
   // and the resolver can suppress unqualified-call binding to those
   // bases per ISO C++ two-phase lookup.
   detectCppDependentBases(tree.rootNode, filePath);
+  captureCppMemberLookupFacts(tree.rootNode, filePath);
 
   return out;
 }

gitnexus/src/core/ingestion/languages/cpp/import-decomposer.ts

@@ -73,6 +73,12 @@ function buildIncludeCapture(node: SyntaxNode, pathNode: SyntaxNode): CaptureMat
  */
 export function splitCppUsingDecl(node: SyntaxNode): CaptureMatch | null {
   if (node.type !== 'using_declaration') return null;
+  // A class-scope `using Base::member;` changes the derived class's member
+  // lookup set; it is not a namespace import. The C++ member-lookup sidecar
+  // captures it separately, so suppress import decomposition here.
+  for (let parent = node.parent; parent !== null; parent = parent.parent) {
+    if (parent.type === 'class_specifier' || parent.type === 'struct_specifier') return null;
+  }
 
   // Check for "namespace" keyword among anonymous children
   let hasNamespaceKeyword = false;